U.S. patent number 5,010,646 [Application Number 07/471,099] was granted by the patent office on 1991-04-30 for shaving system.
This patent grant is currently assigned to The Gillette Company. Invention is credited to Nicolae Neamtu.
United States Patent |
5,010,646 |
Neamtu |
April 30, 1991 |
Shaving system
Abstract
A razor blade member has a first planar portion and a second
planar portion connected to the first planar portion by a
transition bend region. The longitudinal edge of the first planar
portion remote from the transition region is sharpened to a cutting
edge. The blade member also includes stress balancing deformation
along the longitudinal length of the planar portions and adjacent
the transition region. The bow of the second planar portion is less
than 0.05 millimeter per centimeter length of blade member.
Inventors: |
Neamtu; Nicolae (Quincy,
MA) |
Assignee: |
The Gillette Company (Boston,
MA)
|
Family
ID: |
23870248 |
Appl.
No.: |
07/471,099 |
Filed: |
January 26, 1990 |
Current U.S.
Class: |
30/50; 30/41;
30/43.9 |
Current CPC
Class: |
B26B
21/565 (20130101); B26B 21/227 (20130101) |
Current International
Class: |
B26B
21/08 (20060101); B26B 21/22 (20060101); B26B
21/00 (20060101); B26B 21/56 (20060101); B26B
021/00 (); B26B 019/44 (); B26B 019/12 () |
Field of
Search: |
;30/41,42,43.9,48,49,50,52,57,58,78 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Watts; Douglas D.
Assistant Examiner: Heyrana, Sr.; Paul M.
Attorney, Agent or Firm: Fish & Richardson
Claims
What is claimed is:
1. A razor blade member that has a first planar portion and a
second planar portion, said second planar portion being angularly
offset from said first planar portion and connected to said first
planar portion by a transition region, the longitudinal edge of
said first planar portion remote from said transition region being
a cutting edge, and stress balancing deformation along the
longitudinal length of said planar portions and adjacent said
transition region.
2. The blade member as claimed in claim 1 wherein said blade member
is a metal member.
3. The blade member of claim 1 wherein said transition region
between said first and second blade portions has a radius of less
than one millimeter.
4. The blade member of claim 1 wherein said first planar portion is
disposed at an angle of less than 135 degrees with respect to said
second planar portion.
5. The blade member of claim 1 wherein the said second planar
portion has bow of less than 0.05 millimeter per centimeter length
of blade member.
6. The blade member of claim 1 wherein said stress deformation
adjacent said transition region is in the form of corrugations.
7. The blade member of claim 6 wherein said corrugations are of
undulating configuration and said corrugations are spaced less than
two millimeters apart, the dimension between opposing peaks of said
undulating corrugations being less than about 0.2 millimeter.
8. The blade member of claim 6 wherein said corrugations are
equally spaced along the length of said blade member.
9. The blade member of claim 6 wherein said blade member is a metal
member, said first planar portion is disposed at an angle of less
than 135 degrees with respect to said second planar portion, and
said transition region between said first and second blade portions
has a radius of less than one millimeter.
10. The blade member of claim 9 wherein said blade member has a
thickness of less than 0.3 millimeter, and said second planar
portion has bow of less than 0.05 millimeter per centimeter length
of blade member.
11. The blade member of claim 10 wherein said blade member is a
steel member that has a carbon content of about 0.4 percent by
weight and a chromium content of about 13 percent by weight and a
molybdenum content of about 1.25 percent by weight.
12. A razor blade assembly comprising a body member; a blade member
disposed in said body member, said blade member having a first
planar portion and a second planar portion, said second planar
portion being angularly offset from said first planar portion and
connected to said first planar portion by a transition bend region,
the longitudinal edge of said first planar portion remote from said
transition region being a cutting edge, and stress balancing
deformation along the longitudinal length of said planar portions
and adjacent said transition region; structure in said body member
for supporting said blade member for movement relative to said body
member in response to forces encountered during shaving in a
direction along the plane of the second planar portion; and biasing
structure in said body member for urging said cutting edge of said
blade member into a reference position from which it is moved in
response to forces encountered during shaving.
13. The assembly of claim 12 wherein said body member is a one
piece molded member; said support structure includes upstanding
projections integral with said body member that receive and guide
said first planar portion of said blade member; and said biasing
structure includes spring finger structure integral with said body
member.
14. The assembly of claim 13 wherein said assembly includes a guard
member resiliently mounted for movement independently of said blade
member relative to said body member in response to forces
encountered during shaving; and a second blade member resiliently
mounted for movement independently of said blade member relative to
said body member in response to forces encountered during shaving,
said second blade member having a first planar portion and a second
planar portion connected to said first planar portion by a
transition bend region, the longitudinal edge of said first planar
portion remote from said transition region being sharpened to a
cutting edge, and stress balancing deformation along the
longitudinal length of said planar portions and adjacent said
transition region.
15. The assembly of claim 12 wherein said cutting edge has bow of
less than 0.05 millimeter per centimeter length of blade
member.
16. The assembly of claim 12 wherein said stress deformation
adjacent said transition region is in the form of corrugations.
17. The assembly of claim 16 wherein said blade member has a
thickness of less than 0.3 millimeter, said second planar portion
has bow of less than 0.05 millimeter per centimeter length of blade
member, said corrugations are of undulating configuration and are
spaced less than two millimeters apart, and the dimension between
opposing peaks of said undulating corrugations is less than about
0.2 millimeter.
18. The assembly of claim 17 wherein said corrugations are equally
spaced along the length of said blade member.
19. The assembly of claim 18 wherein said blade member is a steel
member that has a carbon content of about 0.4 percent by weight, a
chromium content of about 13 percent by weight, a molybdenum
content of about 1.25 percent by weight, and a hardness of at least
about 100 VON; said first planar portion is disposed at an angle of
about 112 degrees with respect to said second planar portion; and
said transition region between said first and second planar
portions has a radius of less than one millimeter.
20. The assembly of claim 19 wherein said blade member has a
thickness of about 0.1 millimeter, and said second planar portion
has bow of less than 0.05 millimeter per centimeter length of blade
member.
Description
This invention relates to wet shaving systems, and more
particularly to razor blade assemblies for such systems.
Razor blade assemblies in which the blade shaving edge is movable
in response to forces encountered during shaving have been
proposed. Examples of such razor blade assemblies are shown in U.S.
Pat. No. 4,498,235. In shaving systems disclosed in that patent,
guard and blade members are independently movable in response to
shaving forces, and each blade member has a base portion and a
cutting edge portion disposed at an angle to the base portion. When
such blade members are formed by bending a single piece of metal
and the base and cutting edge portions are connected by a bend
transition region, longitudinal distortion is produced which
results in longitudinal curvature in the base portion and similar
longitudinal curvature in the sharpened edge. Such longitudinal
curvatures ("bow") are undesirable, from a standpoint of shaving
geometry, and from the standpoint of reliable movement in response
to forces encountered during shaving and return to the initial
position when the shaving force is released.
In accordance with one aspect of the invention, there is provided a
razor blade member that has a first planar portion and a second
planar portion connected to the first planar portion by a
transition bend region, and the longitudinal edge of the first
planar portion remote from the transition region being sharpened to
a cutting edge. The blade member also includes stress balancing
deformation along the longitudinal length of the planar portions
and adjacent the transition region. The bow of the second planar
portion is less than 0.05 millimeter per centimeter length of blade
member.
While the stress balancing deformation may take a variety of forms,
in preferred embodiments, that deformation is in the form of
corrugations in the two planar portions and do not extend through
the transition bend region, the corrugations in the first planar
portion extending the length of that portion and the corrugations
in the second planar portion terminating about halfway along the
length of that portion. In a particular embodiment, the
corrugations are of undulating configuration and are equally spaced
along the length of the blade member with adjacent peaks less than
two millimeters apart, and the dimension between opposing peaks of
the undulating corrugations being less than about 0.2
millimeter.
In a particular embodiment, the first planar portion is disposed at
an angle of less than 135 degrees with respect to the second planar
portion; the transition region between the first and second blade
portions has a radius of less than one millimeter; the blade member
is a steel member that has a carbon content of about 0.4 percent by
weight, a chromium content of about 13 percent by weight, and a
hardness greater than about 100 VON (Vickers Ocular Number),
In accordance with another aspect of the invention, there is
provided a razor blade assembly that includes a body member; a
blade member disposed in the body member, the blade member having a
first planar portion and a second planar portion connected to the
first planar portion by a transition bend region, the longitudinal
edge of the first planar portion remote from the transition region
being sharpened to a cutting edge, and stress balancing deformation
along the longitudinal length o the planar portions and adjacent
the transition region; structure in the body member for supporting
the blade member for movement relative to the body member in
response to forces encountered during shaving in a direction along
the plane of the second planar portion; and biasing structure in
the body member for urging the cutting edge of the blade member
into a reference position from which it is moved in response to
forces encountered during shaving. The bow of the cutting edge is
less than 0.05 millimeter per centimeter length of blade
member.
In preferred embodiments, the body member is a one-piece molded
member; the support structure includes upstanding projections
integral with the body member that receive and guide the first
planar portion of the blade member; and the biasing structure
includes spring finger structure integral with the body member. In
a particular embodiment, the assembly includes a second blade
member and a guard member, and the two blade members and the guard
members are resiliently mounted for movement independently of one
another relative to the body member in response to forces
encountered during shaving.
Other features and advantages of the invention will be seen as the
following description of a particular embodiment progresses in
conjunction with the drawings in which:
FIG. 1 is a plan view of a razor blade assembly in accordance with
the invention;
FIG. 2 is a front elevational view of the razor assembly shown in
FIG. 1;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is an enlarged side sectional diagrammatic view of a blade
member employed in the razor assembly of FIG. 1; and
FIG. 5 is a diagrammatic top plan view of the blade member shown in
FIG. 4.
DESCRIPTION OF PARTICULAR EMBODIMENT
With reference to FIGS. 1-3, blade assembly 10 includes molded
plastic body member 12 with front and back wall portions 14, 16
that are interconnected by end wall portions 18, 20 and
intermediate frame portions 22, 24 and 26. Back wall portion 16
includes surface 28 that functions as a trailing skin engaging or
"cap" surface and receives an insert member 30 of shave
facilitating material.
As indicated in FIG. 3, formed in each end wall portion is a
leading slot 40 that receives guard member 42; an intermediate slot
44 that receives first blade member 46 and a trailing slot 48 that
receives second blade member 50. Retaining bands 52, 54 on end
walls 18, 26 secure members 42, 46 and 50 in slots 40, 44 and 48,
respectively. Also formed integrally with each end wall are
inwardly extending spring fingers 56, 58 that bias blades 46, 50
upwardly into an initial or reference position in engagement with
retaining bands 52, 54. Further details of a razor assembly of this
type may be had with reference to Jacobson U.S. Pat. No.
4,498,235.
With reference to FIGS. 4 and 5, each blade member 46, 50 is
manufactured of 0.1 millimeter thick stainless steel of the
following composition:
______________________________________ Percent
______________________________________ Carbon 0.47-0.44 Chromium
13.0-14.0 Manganese 0.20-0.50 Silicon 0.20-0.50 Molybdenum
1.15-1.35 ______________________________________
the balance being essentially iron, the blade member having an
hardness of about 98 VON. Each blade is about 3.5 centimeters long
and has a planar base or guide portion 60 that is about 0.2
centimeter long and a planar second portion 62 that is about 0.1
centimeter long and is disposed at an angle of about 112.degree. to
guide portion 60. Portion 62 has sharpened longitudinal edge 64 and
is connected to base portion 60 by transition bend region 66 that
has a radius 67 of about 0.4 millimeter. Formed in portions 60, 62
adjacent to but not extending through transition region 66 are a
series of corrugations 68, 70 that have aligned peaks 72 spaced
about one millimeter apart along the longitudinal length of both
the base portion 60 and the second portion 62. Corrugations 68
extend the length of base portion 60 while corrugations 70 extend
only about halfway along the length of portion 62, as indicated
diagrammatically in FIG. 4. Corrugations 68, 70 distribute and
balance stresses formed by the bending of the blade stock at the
sixty-eight degree bend angle in transition region 66 such that the
guide portion 60 is essentially straight (the "bow" 74 being less
than 0.03 millimeter over the 3.5 centimeter length of the
blade--as indicated by triangles 76, 78). In contrast, a blade with
no corrugations or other stress balancing deformation has a bow of
about 0.1 millimeter over the 3.5 centimeter blade length.
With reference again to FIGS. 1-3, formed on intermediate frame
portions 22 and 26 are a series of upstanding projections 80, 82,
84, the front surface of each projection 82 providing a vertical
guide surface against which the base portion 60 of blade 46 slides
and the front surface of each projection 84 providing a similar
guide surface against which the base portion of trailing blade 50
slides. Similar projections 90, 92, 94 and 96 are upstanding from
intermediate frame portion 24. The rear surface of projection 90
cooperates with the front surfaces of projections 92 and 94 to
define a guidance region for the base portion 60 of leading blade
46; and rear surfaces of projections 92 and 94 cooperate with the
front surface of projection 96 to provide a central guidance region
for the base portion of trailing blade 50.
Spring fingers 98, that are molded integrally with intermediate
frame portions 24 and 26 and extend outwardly in opposite
directions, engage the lower surface of guard member 42 and bias
that guard member upwardly against the retaining bands 52, 54 in
position indicated in FIG. 3.
Similarly, the blades 46, 50 with stress balancing corrugations 68,
70 are received in the guide passages defined by the upstanding
projections 80-84 and 90-96; are biased upwardly against the
retaining bands 52, 54 in position indicated in FIG. 3 by spring
fingers 56 and 58; and slide freely against the upward biasing
influence of those spring fingers in response to forces encountered
during shaving.
During a shaving operation, the second blade 50 trails the first
blade 46 as the assembly travels over the surface being shaved, and
the guard 42 and blades 46, 50 move independently of each other
against the bias of the spring fingers.
While a particular embodiment of the invention has been shown and
described, various modification will be apparent to those skilled
in the art, and therefore it is not intended that the invention be
limited to the disclosed embodiment, or to details thereof, and
departures may be made therefrom within the spirit and scope of the
invention.
* * * * *